It has long been the practice to use crown moldings to cover and decorate the junctures of room walls and ceilings, and to provide ornamentation on the exposed outer sides of the crown moldings as additional room decoration. Current examples of such crown moldings are shown in U.S. Pat. Nos. 5,433,048, 5,662,753 and 5,398,469, and older approaches are shown in U.S. Pat. Nos. 2,981,988, 3,201,910 and 3,481,092. It will be seen in these patents that there are numerous ways to design, manufacture and install crown moldings and a variety of different materials that may be used. As stated in the Loos patent, U.S. Pat. No. 5,662,753, the manufacture of ornamental molding made of plaster has required a relatively high skill level, either to run the molding "in place" on a wall or ceiling, or to cast the molding in elongated strips in stationary molds and then to mount the strips on the supporting room surfaces. It is generally accepted that plaster moldings, whether run-in-place or cast in stationary molds, are the richest looking and generally provide the most elegant appearance, but cost often leads to the use of cheaper substitutes.
Loos, for example, proposes the use of a relatively complex substitute for traditional plaster crown moldings, using a special base molding in an attempt to avoid the need for expensive production techniques and highly skilled labor. The other patents cited above provide other approaches for the same general purpose.